The present invention relates to a field glass having means for alternative observation of additional information.
Field glasses are already known in which additional information, such as direction, is superimposed on the image plane. The disadvantage of these known embodiments is that part of the image plane is permanently used for the additional information so that the total image plane can never be utilized for observing the primary information. Such field glasses are described for example in British patent no. 1 603 599 and German utility model no. 83 01 958.
Field glasses are also known in which an LC (liquid crystal) information carrier takes up the whole image plane. However such devices have the disadvantage that they involve a considerable loss of light.
European patent no. 170 655 also describes a means for reflecting additional information into a field glass. The additional information is additionally superimposed on the beam path. The disadvantage here is the technically elaborate and voluminous construction.